FIELD OF THE INVENTION
Perhaps the most difficult skill to be acquired by a welder is to cut circles with a cutting torch to close tolerances. Prior art devices have been developed which make an attempt at cutting circles which have adjustable features, and these patents include U.S. Pat. Nos. 1,495,994, 1,792,317, 2,323,298, 2,452,718 and 2,688,190.
They can all be characterized by the following limitations. They are quite complex and are difficult to adjust therefore creating unnecessary demands upon the user in terms of time and cost expenditure, and further are limited in accuracy by virtue of the inherent play in these complex mechanisms.